Improve extraction of section texts from Markdown headings

[davorpa]

According to current code...

free-programming-books-parser/index.js

Lines 192 to 212 in 5eaf00b

	if (item.type == "heading") {
	if (item.depth == 3) {
	// Heading is an h3
	currentDepth = 3;
	let newSection = {
	section: item.children[0].value, // Get the name of the section
	entries: [],
	subsections: [],
	};
	sections.push(newSection); // Push the section to the output array
	} else if (item.depth == 4) {
	// Heading is an h4
	currentDepth = 4;
	let newSubsection = {
	section: item.children[0].value, // Get the name of the subsection
	entries: [],
	};
	sections[sections.length - 1].subsections.push(newSubsection); // Add to subsection array of most recent h3
	}
	} else if (item.type == "list") {
	item.children.forEach((listItem) => {

it seems that the parser not supports HTML anchor aliases neither Markdown syntax. It takes for granted that childrens[0] will be plain text.

It's necesary make a ES6 Array.reduce of the heading item.children taking into account all cases in order to rebuild the desired text. Cases type:

• html, link: ignore record. maybe an anchor alias or a back to top/upper section link
• text: append value
• emphasis: append children values wrapping between _ (italic Markdown tokens)
• strong: append children values wrapping between ** (bold Markdown tokens)
• ...